How Alicia Vikander put on 12 pounds of muscle for 'Tomb Raider' transformation

Alicia Vikander admits she’s always been “petite.” The Swedish Oscar winner (The Danish Girl) and former ballet dancer stands 5-foot-5 and has always had a featherweight frame.

But you wouldn’t want to cross her in Lara Croft mode.

Vikander, 29, added about 12 pounds of muscle to play the video-game-turned-action-movie heroine in the new reboot of Tomb Raider (a role previously played on the big screen by Angelina Jolie in 2001 and 2003).

“I lifted weights, probably for the first time in my life, to be able to put on that muscle,” Vikander told Yahoo Entertainment at the film’s Los Angeles press day (watch above). “And I had some really incredible women who I met who trained me in MMA [mixed martial arts] and boxing.”

In the origin story, Croft is a London bike messenger who trains in MMA — and refuses to acknowledge the death of her missing explorer father (Dominic West), which prevents the heiress from claiming his vast fortune. She ultimately finds a clue about his whereabouts, which sends her to a remote island off the coast of Japan, where her first Tomb Raid begins.

“I’m quite petite, so I put on 10 to 12 pounds because I wanted to honor the fact that in the story she’s this very feminine young woman, but she has physical strength, so it’s plausible for you to believe that she can do what she does when she’s thrown out on this adventure.”